[Bug tree-optimization/78429] [7 Regression] ice on valid C code on x86_64-linux-gnu at -O3 in both 32-bit and 64-bit modes (internal compiler error: in set_value_range, at tree-vrp.c:361)

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78429

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
It looks like this guard in set_and_canonicalize_value_range:

      /* For one bit precision if max < min, then the swapped
         range covers all values, so for VR_RANGE it is varying and
         for VR_ANTI_RANGE empty range, so drop to varying as well.  */
      if (TYPE_PRECISION (TREE_TYPE (min)) == 1)
        {
          set_value_range_to_varying (vr);
          return;
        }

is bypassed because we have a rather surprising boolean type:

(gdb) p debug_tree(min)
 <integer_cst 0x7ffff6d85c90 type <boolean_type 0x7ffff6d7b888> constant 0>

(gdb) p debug_tree((tree)0x7ffff6d7b888)
 <boolean_type 0x7ffff6d7b888 public SI
    size <integer_cst 0x7ffff6c34ee8 type <integer_type 0x7ffff6c39150
bitsizetype> constant 32>
    unit size <integer_cst 0x7ffff6c34f00 type <integer_type 0x7ffff6c390a8
sizetype> constant 4>
    align 32 symtab 0 alias set -1 canonical type 0x7ffff6d7b888 precision 32
min <integer_cst 0x7ffff6d85a20 -2147483648> max <integer_cst 0x7ffff6d85bb8
2147483647>>